The majority of carcinosarcomas showed at least focal PD-L1 expression, predominantly in tumor-associated immune cells. Carcinosarcomas with endometrioid morphology were significantly more likely to have high-level PD-L1 (5/7 vs. 7/34; P=0.015). MMR-deficient carcinosarcomas were also more likely to have high-level PD-L1 (2/3 vs. 10/28); however, this did not reach statistical significance (P=0.2) and overall MMR-deficiency was uncommon (3 cases, 7%). These findings suggest that PD-L1 may be additive to MMR testing as a predictive biomarker for checkpoint inhibitor vulnerability in carcinosarcomas.The phenomenon of small human papillomavirus-associated cervical adenocarcinomas involving the ovary via a transuterine and transtubal route is uncommon but well described in the literature. We report a unique case of a small human papillomavirus-associated cervical adenocarcinoma spreading to both ovaries and the pelvis via this route 22?mo after loop excision and trachelectomy and developing into a high-grade neuroendocrine carcinoma in the metastasis.Endometriosis is generally histopathologically defined as the presence of at least 2 of the following endometrial stroma, Müllerian epithelium, and/or hemosiderin-laden macrophages (HLM). Despite clinically evident endometriotic lesions, biopsies are frequently nondiagnostic. In this study, we conducted a large-scale review of biopsies of lesions clinically thought to represent endometriosis and correlate the histologic findings with clinical appearance to expand sensitivity of the pathologic definition of endometriosis, particularly in patients on hormonal therapy. In all, 112 biopsies from 78 patients (mean age=25, range 18-39?yr) were reviewed for histopathologic features suggestive of or diagnostic for endometriosis including the presence of endometrial stroma, Müllerian epithelium, dystrophic calcifications, HLM, chronic inflammation, adhesions, and vascular proliferation. Endometriosis was confirmed by pathologic criteria in 37 of 78 patients (47%). Biopsies from patients on hormonal therapy (n=62, 80%) were significantly less likely to meet pathologic criteria for endometriosis (P=0.01). Nondiagnostic biopsies (70/112; 63%) frequently displayed HLM (20%), chronic inflammation (29%), dystrophic calcifications (26%), vascular proliferation (20%), or adhesions (20%) and were significantly more likely to have a vascular clinical appearance (P=0.01). Diagnostic biopsies (42/112; 38%) were more likely to have a blue/black clinical appearance (P=0.03), demonstrate HLM (P=0.004), and display pseudodecidualization (P=0.05). https://www.selleckchem.com/products/ferrostatin-1.html Patients with a high clinical suspicion of endometriosis have a range of histologic findings, with less than half meeting the current histopathologic criteria for diagnosing endometriosis. Given the heterogeneous histopathologic appearance, revision of the histologic criteria may be warranted with further exploration, particularly for lesions with predominantly vascular features.Although histiocytic lesions of the fallopian tube are relatively rare compared to their epithelial counterparts, there exists a spectrum of histiocytic lesions involving the fallopian tube that are described under different terminologies dependent on the involved compartment of the fallopian tube. A common histologic denominator of all the hitherto reported tubal histiocytic lesions is the presence of sheets and clusters of histiocytes without any supportive connective tissue. The current study describes three cases of a heretofore-undescribed papillary histiocytic lesion in the lumen of the fallopian tube. All 3 lesions were characterized by avascular, hyaline collagenous papillary cores surrounded by a monotonous population of epithelioid cells, morphologically resembling mesothelial cell hyperplasia, but displaying a histiocytic immunophenotype with diffuse immunopositivity for CD68. Since the papillary cores did not harbor any vasculature, the term intratubal pseudopapillary histiocytic hyperplasia was proposed for this histiocytic proliferation which expands the spectrum of histiocytic lesions of the fallopian tube. Although probably of no clinical significance, practicing pathologists should be aware of this peculiar histiocytic lesion of the fallopian tube to avoid misdiagnosis and unnecessary immunohistochemical testing.Recurrent vulvar squamous cell carcinomas (SCCs) are a poorly understood and aggressive group of treatment-resistant neoplasms. Currently, it remains unclear whether these are in fact recurrences of the same primary tumor, or the development of entirely new tumors. Here, to address this question, we examined the mutational profile of a series of patients with recurrent or multifocal non-human papilloma virus (HPV)-associated vulvar SCC. We performed a targeted 33-gene next-generation sequencing panel on a series of 14 patients with recurrent or multifocal non-HPV-associated vulvar SCC and precursor neoplasms. This amounted to 54 cases (33 SCC, 1 verrucous carcinoma, 13 differentiated vulvar intraepithelial neoplasia, and 7 differentiated exophytic vulvar intraepithelial lesion), with 79 mutations detected altogether. TP53 [51/79 (65%)] was the most frequently mutated gene. Mutations in PIK3CA [16/79 (20%)), HRAS [6/79 (8%)], PTEN [4/79 (5%)], EGFR [1/79 (1%)], and GNAS [1/79 (1%)] were occasionally seen. Most patients with SCC [5/9 (56%)] recurrent, 4/5 (80%) multifocal] demonstrated a clonal relationship, and harbored the same mutations in the same genes in metachronous or synchronous tumors. A subset of the recurrent tumors [2/5 (40%)] recurred with additional mutations. These clonal relationships were shared between SCC and differentiated vulvar intraepithelial neoplasia in each case. By contrast, a small number of recurrent tumors [3/9 (33%)] demonstrated novel mutations, entirely different from the primary tumor. Thus, our findings suggest that recurrent non-HPV-associated vulvar SCC can arise from 2 mechanisms.Carcinosarcomas (CSs) of the endometrium are biphasic malignancies, composed of high-grade carcinomatous and sarcomatous components. Surgical stage and pathologic characteristics are the most important prognostic findings, with a 5-yr survival of 15% to 30% in advance stage disease. Folate receptor alpha (FRA) overexpression has been observed in endometrial carcinomas and not yet studied in CSs. This study evaluates semiquantitative expression of FRA in both carcinomatous and sarcomatous components of CSs on whole tissue sections. Immunohistochemistry for FRA expression was performed and extent and intensity of staining were recorded for each case for both histologic components. A total of 46 cases were stained for FRA. The majority of these (40/46, 87%) showed FRA staining at variable intensity in the carcinomatous component, stronger in serous carcinomas and high-grade endometrioid, while only a small subset of tumors demonstrated weak staining in the sarcomatous component (2/46, 4.35%). CS is known to be associated with poor prognosis and adjuvant therapy is recommended even in low stage disease.